Integrated circuits (ICs) are typically formed on a semiconductor wafer. The semiconductor wafer is then mounted on adhesive tape and the wafer is cut into individual dies using a wafer saw. In general, the adhesive tape provides support for the wafer during the die cutting operation. Typically the wafer saw cuts the wafer into separate die while not cutting through the adhesive tape. The dies are then individually separated from the adhesive tape for transfer to packaging.
A variety of techniques have been used to separate the dies from the adhesive tape. As one example, ejector pins (sometimes referred to as plunge-up needles) have been used to separate the dies. In these techniques the ejector pins are projected from a needle holder and push the die from underneath through openings in an anvil. This causes the die and the adhesive tape to disengage from one another. The separated die can then be picked up and transferred to a die transfer pack or the packaging substrate.
Such techniques have several disadvantages. For example, while the use of ejector pins can be effective for relatively thick dies, such techniques can be problematic when applied to thinner dies that are increasingly used for modern integrated circuits. Specifically, on thinner dies the use of ejector pins to separate the die from adhesive tape can result various types of die cracks. Such die cracks can result in lower yield for final packaged devices and/or lower long term reliability.
For this reason there is a continuing need for improved devices and techniques for separating semiconductor die from adhesive tape.